You'll definitely need to start off with the log files to see if there is anything happening that has been logged. That will be your starting point. If you do come across anything in the logs, share it here and hopefully it should help to point to the right direction.

We had the similar issue on 12.2.1.3, we also raised multiple SR's but still sending adplus logs and diagnostics dumps. Waiting for dev team to respond.

BUT we have some workarounds.

First of all you better check your RDP, we found some unmapped columns while consistency checker finds no warning or error on mentioned column. I can suggest you to check all mappings and logical table sources.

Second, when you seed cache with agents and then access to report from cache, again nqsserver.exe crashes. So we disabled cache totally, now the system is OK.